An expensive way to do that is to build new single-warhead missiles.

The rival option would be to switch to a single-warhead missile, the Midgetman.

American intelligence estimates China has between 16 and 20 single-warhead nuclear missiles.

At the same time, the Pentagon had eliminated all but $200 million for a single-warhead nuclear missile, the Midgetman.

In addition, there are 100 SS-4 single-warhead missiles that are gradually being replaced.

If each side had only a force of single-warhead missiles, it would have no incentive to launch a pre-emptive strike, proponents say.

Going to a single-warhead missile would drop the total to 500 warheads on 500 missiles, he said.

The study concluded that Midgetman would cost not $40 billion but $29.8 billion, for 500 single-warhead mobile missiles.

The remaining 40 or so regiments, each with nine single-warhead missiles, remain in garrison.

It also plans to build a new single-warhead missile, the Midgetman, which can be truck-mounted.